Control of combustion phasing in an internal combustion engine is useful when applied to EGR (exhaust gas recirculation), fuel injection timing, and cylinder cooling strategies. Poor calibration however may at times cause undesired engine operation, such as misfire in ranges where EGR rates are high. Non-uniform EGR distribution or in-cylinder cooling can also lead to cylinder-to-cylinder variability of combustion phasing.
The applicants believe that control of intake valve closing (IVC) on an individual engine cylinder basis can provide better overall control of a multi-cylinder diesel engine. Control can be further improved in the presence of a combustion phasing feedback, such as cylinder pressure or ion sensing technology.